Towards understanding factors that govern fertilizer response in casave: lessons from East Africa

Information on fertilizer response in cassava in Africa is scarce. We conducted a series of on-farm and on-station trials in two consecutive years to quantify yield responses of cassava to mineral fertilizer in Kenya and Uganda and to evaluate factors governing the responses. Average unfertilized yields ranged from 4.2 to 25.7 t ha-1 between sites and years. Mineral fertilizer use increased yields significantly, but response to fertilizer was highly variable (-0.2 to 15.3 t ha-1). Average yield response per kg applied nutrient was 37, 168 and 45 and 106, 482 and 128 kg fresh yield per kg of applied N, P and K, respectively in 2004 and 2005. Fertilizer response was governed by soil fertility, rainfall and weed management, but was not influenced by variety, pest and disease pressure and harvest age. Relative N and K yields were positively correlated to SOC and exchangeable K, while response to fertilizer decreased on more fertile soils. Still, fertilizer response varied widely on low fertility soils (e.g. on soils wit

Aflatoxins contamination in processed cassava in Malawi and Zambia

Strains of the Aspergillus fungi, especially A. flavus and A. parasiticus, primarily produce aflatoxins which are a major health concern to man and livestock because of their acute and chronic health effects. Aflatoxins pose the greatest risk to health in tropical Africa because of their widespread prevalence and high toxicity; carcinogenic (cause liver and esophageal cancer) effect, immune system suppressing and anti-nutritional  contaminants in many food commodities and even cause death. Aflatoxins have also been reported to compromise vaccine efficacy in experimental animals. Due to the seriousness of aflatoxins, international agencies have restricted levels of aflatoxins to 20 ppb in food materials as the maximum permissible level in the United States and 4 ppb total aflatoxins and under 2 ppb aflatoxin B1 in Europe. These regulations directed at minimizing human exposure to aflatoxins results in severe economic loss to producers, processors and marketers of the contaminated crop. A study was conducted in Malawi and Zambia to assess the level of fungal and mycotoxins’ contamination in commonly processed cassava products. A total of 92 and 88 samples of processed cassava products comprising makaka, flour, kanyakaska, kadonoska, scrapes and grates were collected in the rainy season of 2008 and 2009 in Malawi, respectively. Further, 22 samples of processed cassava products comprising dried cassava chips and flour were collected in the rainy season of 2009 in Zambia. The samples were analyzed for fungal and aflatoxins B1, B2, G1 and G2 contamination using the Romer mini-column method and the VICAM AflaTest  immunoaffinity fluorometric method. None of the samples in 2008 were contaminated with aflatoxins. Similar results were obtained in 2009 with almost all the samples in Malawi and Zambia having aflatoxin levels much lower (<2.0 ìg/kg in Malawi and <4.2 ìg/kg in Zambia) than the Codex Alimentarius Commission (CAC) maximum permissible level of aflatoxins of 10.0 ìg/kg, implying that the cassava products analyzed were safe for human consumption. However, further studies are needed to cover a larger sample size over a period of a year to represent all seasons in the cassava producing and consuming areas and conclusively make certain the safety of these products for human consumption.Key words: Cassava, consumption, aflatoxin, food, safet

Evaluation of nutritional properties of cassava-legumes snacks for domestic consumption: consumer acceptance and willingness to pay in Zambia

Open Access JournalHigh-quality cassava flour (HQCF) is a cheaper alternative to wheat in the production of snacks. This study assessed the nutritional properties and consumer acceptability of cassava-legume snacks in Zambia. Cassava snacks were made from 100% HQCF, 50:50 cassava-soybean flour blend, 50:50 cassava-cowpea flour blend and 100% wheat flour as the control. The samples were analyzed for nutritional, functional and anti-nutritional properties using standard laboratory methods. Also, a well-outlined questionnaire was used to collect data on consumer preferences. The results showed a significant (P 0.05). There was a significant (P < 0.05) increase in ash, protein and fat contents but a decrease in total sugars, amylose and starch contents of the legume-fortified snacks when compared with 100% cassava snacks. Cassava-legume snacks had a high acceptance in Kasama, Kaoma and Mansa districts, with a better preference for the cowpea variant of tidbit. There was a positive linear relationship between snack sensory characteristics (aroma, taste and texture) and consumer willingness-to-pay (WTP). The results show that snacks that are acceptable, affordable, nutritious and of excellent preference characteristics can be produced from cassava and legumes for households in Zambia

Effects of genotype by environment interaction on agronomic and functional flour properties among cassava genotypes targeted for industrial use

Open Access ArticleThe study was carried out to evaluate the genotype by environment (G × E) interaction on physicochemical and functional properties of ten (10) cassava advanced genotypes and improved varieties. The genotypes and varieties were collected from a multi-location trial (Uniform yield) of the IITA breeding program at four research stations in Malawi. Based on the results, G × E interaction was highly significant (P ≤ 0.001) in explaining the variance of the physicochemical parameters and functional properties. Thus, G × E interaction highly influenced starch and amylopectin contents, swelling power, and water binding capacity. Additive main effect and multiplicative interaction (AMMI) analysis identified I010040, MM06/0045 and TMSL110080 genotypes and Mbundumali, Mpale and Sagonja varieties as the most stable with high yield performance hence recommended for cultivation in a wide range of environments for the production of high quality cassava flour (HQCF) and starch for various industrial applications such as the production of ethanol, biofuels, starch and glucose syrup in chemical industries; thickeners, stabilizers, and texture modifiers in food, bakery and confectionery industries

Nutritional quality of fritters produced from fresh cassava roots, high-quality cassava and soy flour blends, and consumer preferences

Open Access Journal; Published online: 09 Oct 2019Fritters are flour-based snacks made from wheat flour, but a cheaper alternative is needed in a developing economy, such as Zambia, owing to the high cost of wheat. This study aimed at evaluating fritters produced from different sources: fresh cassava roots, high-quality cassava flour (HQCF), and a composite (80:20) of HQCF and high-quality soy flour (HQSF) using 100% wheat flour as the control. The nutritional and anti-nutritional properties were analyzed with standard laboratory methods. A structured questionnaire was used to analyze consumer preferences. There were significant (P 0.05) differences in the antinutritional properties among cassava and wheat fritters except for the composite cassava‒soybean fritters. Among respondents from Kaoma, Kasama, and Serenje, the sensory characteristics showed no significant (P > 0.05) differences for appearance and aroma of all the fritters samples. The results showed that HQCF fortified with HQSF could be used as a cheaper alternative to wheat flour in the production of nutritious and acceptable fritters

Data on assessment of flours from advanced genotypes and improved cassava varieties for industrial applications

Open Access Journal; Published online: 28 Aug 2021The data presented in this article are related to the research paper “Physicochemical parameters and functional properties of flours from advanced genotypes and improved cassava varieties for industrial applications” [1]. The genotypes were collected from a multi-location (Uniform yield Trial) trial of the IITA breeding program in Malawi. The data were obtained using multiple analytical techniques and methodology such as oven-drying, sieving, colorimetry, titration, acid hydrolysis method, the Kjeldahl procedure, UV/VIS spectrophotometry, and centrifugation.The data set contains physicochemical parameters described dry matter (on fresh weight basis), moisture content, pH and total titratable acidy, the content of ash, bulk density; chemical properties were described by total cyanogen potential, total starch, amylose, amylopectin, crude protein and total carbohydrates; functional properties were described by swelling power, water solubility, water binding capacity and oil absorption capacity. The presented data are valuable for cassava breeders, food scientists, nutritionists, and other researchers working on breeding and processing cassava for innovative product development from cassava flour

Elite cassava clones (Manihot esculenta) grown in Zambia: effects of drying techniques on their chemical, functional, and pasting properties.

Open Access Journal; Published online: 15 Jun 2023Introduction: Cassava (Manihot esculanta) is becoming an important crop in most developing countries, especially Zambia. However, cassava roots deteriorate quickly after harvest, producing flour or chips of sub-optimal quality. Hence the evaluation of processing procedures to extend the product’s shelf-life cannot be overemphasized. This study investigated the effects of different drying methods on the chemical, functional and pasting properties of selected advanced cassava clones grown in Zambia. Methods: Fresh Roots of the seven cassava clones (harvested 12 months after planting) were sampled, peeled, washed and dried using the three drying methods (sun-drying, oven-drying and freeze-drying). The flour samples from these drying methods were analyzed using standard laboratory methods for primary chemical, functional and pasting properties. The data generated were statistically analyzed for descriptive, analysis of variance (ANOVA), and the means were separated at p< 0.05. Results and discussion: The clone and drying method had significant effects (p sun > freeze drying. Generally, the highest sugar content was recorded for the freeze-dried samples. Similarly, the total starch content was higher in the sun-dried samples of six out of the seven samples than in the oven-dried samples. The functional properties ranged from 31.29–61.04%, 2.31–5.41%, 119.68–206.78% and 54–70 for solubility, swelling power, water absorption capacity and dispersibility, respectively. Conclusion: In conclusion, the clonal effect of the cassava and drying method significantly affected the cassava flours’ color, chemical, functional, and pasting properties

Physicochemical, microbial, and aflatoxin analyses of selected high-quality cassava flour (HQCF) from the major markets of Zambia

Open Access Journal; Published online: 13 May 2021Various quality grades of high-quality cassava flour (HQCF) are found in markets due to the rapid increase in its utilization for product development. Therefore, this study assessed the chemical, functional and pasting properties and the microbial and aflatoxin content of HQCF being sold in Lusaka markets. Nine samples of HQCF (coded CM 01 to 09) were collected from supermarkets, one major open market, and one cassava processing centre. The samples were analyzed for chemical, functional and pasting properties and the microbial and aflatoxin content using standard laboratory methods. Samples CM 01, CM 08, and CM 09 had starch content above 60%, while CM 02 to CM 07 had starch slightly above 40%. The mean value of bulk density (BD) was 0.51 ± 25.49 g ml−1, dispersibility 68 ± 2.63%, swelling power (SP) 7.84 ± 0.76%, solubility index 135.80 ± 18.8%, and water absorption capacity (WAC) 6.28 ± 32.49%. The mean value for the peak viscosity was 437.46 ± 94.12 RVU, trough viscosity 217.55 ± 27.41 RVU, breakdown viscosity 219.91 ± 77.94 RVU, final viscosity 284.31 ± 29.96 RVU, and setback viscosity 66.77 ± 5.30 RVU. There was no detection of aflatoxins B1, B2, G1, and G2, especially aflatoxin B1 (AFB1) that belongs to group 1 carcinogens for humans. Bacteria colony counts in samples CM 02, CM 03, CM 07, and CM 09 were higher with CFU mg−1 of 2,280,000, 260,000, 200,000, and 510,000, respectively. The study’s information will guide the quality standard specifications, breeding programs, and end-use of HQCF